The antibacterial compound cephalosporin C was first isolated by Newton and Abraham (Nature, 175:548, 1955). Cephalosporin C is produced by fermentation, generally by the organism cephalosporium acremonium. ##STR1## 7-Aminocephalosporanic acid (7-ACA), 1, is an important intermediate in the synthesis of many cephalosporin antibiotics. It is generally obtained from cephalosporin C following chemical cleavage of the acyl group attached to the 7-amino substituent.
Deacetyl cephalosporin C is a major by-product in the fermentation and is converted to deacetyl 7-ACA, 2, in the process of converting cephalosporin C to 7-ACA. The problem associated with the formation of these side products on the yield of 7-ACA, and a possible solution to this problem is offered in U.S. Pat. No. 5,221,739 and U.S. Pat. No. 4,908,444. More specifically, they teach the direct reacylation of 3-hydroxymethyl-3-cephem-4-carboxylic acids in an aqueous medium.